Is Global Warming real?

This is not new news. These changes
started 18,000 years ago, as the earth emerged from the Pleistocene Ice
Age-- a time when ice-covered mammoths and mastodons roamed the earth.

Geologists know great ice sheets once
covered large portions of the continents. These glaciers have alternately
retreated and advanced as the earth has warmed and cooled, in cycles spanning
hundreds, thousands, and millions of years.

Historical data from ocean sediments and
ice cores indicate warm interglacial periods of 15,000 - 20,000 years separate
each major ice age. We currently are in an interglacial period, and are
due ( some say overdue ) for the next 100,000- year Ice Age.

Earth's Icehouse History

Beginning
about 18,000 years ago the Earth started warming up, halting at least temporarily
a 100,000-year-long Ice Age, during which the upper latitudes of almost
all the continents lay buried under thick sheets of glacial ice.

The Earth was a much colder and drier place then. Deserts were more
extensive, summers were short, and winters brutal. Approximately 1/5 of
the forests on the planet were obliterated by the great ice sheets. Over
1/2 of the continent of North America was a desolate wasteland of ice.

At the peak of glaciation, oceans were 300 feet lower than they are
today, allowing animals and men to walk from Siberia to Alaska across the
Aleutian Land Bridge, causing changes to the ecosystem of North America.
It wasn't until about 15,000 years ago that global warming caused the great
glaciers to retreat, allowing establishment of our accustomed environment.
Average global temperatures have risen about 5° C since the last Ice
Age.

The Role of the Greenhouse Effect

From an historical perspective,
global warming has saved us, at least temporarily, from an Icehouse Climate,
although humans can hardly take the credit.

3) The influence of plate tectonics
on the distribution of continents and oceans

4) The so-called "greenhouse effect,"
caused by atmospheric gases such as gaseous water vapor (not droplets),
carbon dioxide, methane, and nitrous oxides, which help to trap radiant
heat which might otherwise escape into space.

The "greenhouse effect"
actually is a bit player in global climate (although without it's benefits
the average temperature of the Earth would be minus 18° C).
Human's did not cause the greenhouse effect, but critics maintain human
additions to atmospheric greenhouse gases may cause global temperatures
to rise too much.

Generally understood, but rarely publicized is the fact that 95%
of the greenhouse effect is due solely to natural water vapor. Of the
remaining 5%, only 0.2% to 0.3% of the greenhouse effect (depending on
whose numbers you use) is due to emissions
of carbon dioxide and other gases from human sources. If we are in
fact in a global warming crisis, even the most aggressive and costly proposals
for limiting industrial carbon dioxide emissions would have an undetectable
effect on global climate. However, significant efforts to limit the emission
of greenhouse gases in the United States are currently underway.

Carbon Dioxidefrom all coal burning
worldwide comprises only 0.013% of
the greenhouse gases in Earth's atmosphere.

Ready... fire... aim?

In Kyoto,
Japan in December 1997 former President Clinton and former Vice President
Gore agreed to commit the United States to significant future reductions
of carbon dioxide emissions, principally by cutting the use of fossil fuels
by as much as 30% over the next 10 years. It is assumed that these drastic
proposed measures will have a real effect on protecting Earth's climate--
an assertion that many climate experts are reluctant to support.

While scientists are currently searching for proof that emissions from
the burning of fossil fuels are warming the planet, there exists no solid
proof at this time.

The strongest evidence for a problematic greenhouse effect is data generated
from computer models which predict about 1.5° C of warming in the next
50 years unless something is done to change the rate of carbon dioxide
entering the atmosphere.

While computer climate models may eventually be able to predict future
climate change, so far the ones we have are very unreliable-- unable even
to accurately predict current climate conditions using current climate
data.

"Right
now I do not have confidence that changes in sea ice and clouds are done
correctly in climate models. The annual cycle is not correct in many models,
so why should it be correct in climate change [projections]?"

Kevin Trenberth,head of climate analysis at the National
Center for Atmospheric Research in Boulder, Colo. ( in an interview for
the Washington
Post, May 1998 ).

It will be some time before computer models will be able to reliably
predict future climate change. Meanwhile, policy-makers like the United
Nations and the Clinton/Gore Administration contend that we do not have
time to wait.

Economists
fear putting the United States on a strict carbon diet could stall
a booming U.S. economy and reignite inflation.

Prominent climatologists like Dr. Richard Lindzen of MIT and Dr. Patrick
Michaels of the University of Virginia contend that we would do well to
carefully consider what the greater body of scientific evidence has to
say on the matter of global warming before taking drastic measures. Their
concerns are shared by other scientists who are troubled that the issue
of global warming seems driven more by politics than by sound
science.

Geologic history clearly shows that Earth's climate is dynamic and ever-changing.
While carbon dioxide as a constituent of Earth's atmosphere has been increasing
since the industrial revolution, it has been similarly increasing since
the earth started warming 18,000 years ago. Clearly, there are natural
forces at work.

All sides agree the subject of climate change is a complex one. Prudent
science maintains that in our pursuit to understand our climate future
we must also understand Earth's climate past. Toward this objective the
next page explores Earth's climate history over the last 750,000 years--
essential reading if you are concerned about or interested in the issue
of global warming.